There is a heat exchanger in which an inside of a first header collecting pipe to which a plurality of flat pipes are connected is partitioned into a communication chamber and a mixing chamber by a vertical partition wall, and the communication chamber is partitioned by a horizontal partition plate.
In addition, there is a refrigerant distributor in which a cylindrical metal net or foam metal is inserted between an outer pipe, to which a plurality of branch pipes for flowing a refrigerant are connected, and an internal pipe, which is accommodated in the outer pipe and has a plurality of refrigerant outflow holes.
Related technique is disclosed in International Publication Pamphlet No. WO 2013/076993 or Japanese Laid-open Patent Publication No. 2012-2475.